Single Responsibility Principle (SRP)says that "THERE SHOULD NEVER BE MORE THAN ONE REASON FOR A CLASS TO CHANGE.". Although this article mentions only about class, I think the SRP also applies to methods within the class: there should never be more than one reason for a method to change.Visual Studio provides a good way to mark off section of file in the form of "region"so they can be collapsible and the code can be organized. Many people use region in a big method to organize the code. For example:

public void CreeateOrder(/*some parameters*/)
{
#region Validate the parameters
//code goes here
#endregion
#region create the order
//insert the order data in the database
#endregion
#region create the order item
//insert the item data in the database
#endregion
}

Note that not all people use regions like this. Many people use comments instead of regions in this kind of methods.As you can see this is a clear violation of the single responsibility principle. The method does more than one thing: it validates the order data, create a top level order and create order items. This can certainly be put into separate method.